11/24/2014 07:03 EST | Updated 01/24/2015 05:59 EST

B.C. man on trial for murder admits killing wife, but says she was attacking him

KAMLOOPS, B.C. - A British Columbia man charged with second-degree murder in the death of his girlfriend admits he killed her, but says it was an accident that happened during a drug-fuelled fight.

"I didn't want anybody to die," Robert Balbar, 42, told a jury Monday as he took the stand in his own defence.

"The last thing I wanted was for anybody to die. I was just in a panic."

The body of 31-year-old Heather Hamill was found floating in the North Thompson River on Aug. 1, 2003. She had been bludgeoned to death with a blunt object.

Balbar told the jury he killed Hamill during a confrontation in late July of that year.

Balbar said he was having a quiet night at his apartment, where his nine-year-old son was sleeping over, when Hamill showed up and pushed her way inside. He said she was pacing around his apartment, taking swigs from a brown methadone bottle, when she eventually started throwing items around the suite.

"The more I tried to calm her down, the more violent she got," he said.

Balbar said Hamill eventually picked up a hunting knife and chased him around the apartment. He said he wrestled it away from her and hid it in a kitchen cupboard, out of her reach.

When he left the kitchen, Balbar said, he noticed the door to his son's bedroom was open and that Hamill had gone into the room.

"Soon as I walked in, I seen she had a machete," Balbar said.

"I immediately froze and put my hands up so she could see I had nothing with me. She had the thing pointed towards my son's head and she was poking it at him while she was looking at me. I just wanted her to calm down at that time."

Balbar said he then left the bedroom to grab a mechanic's hammer from the living room. He said Hamill followed him, eventually swinging the machete at him as soon as he picked up the hammer.

"She was trying to take my head off with it," he said. "I was doing my best to not get hit by the machete."

Balbar said Hamill eventually tripped, which is when he went on the offensive.

"When I had the opportunity, I just flailed the hammer as hard as I could and tried to knock her out," he said.

"I hit her a few times. She fell onto my legs and I hit her two more times with the hammer, then I went into the bedroom to check on my son, to make sure she didn't hit him on her way out."

Balbar said his son was still sleeping. When he went out to the living room to check on Hamill, he said, she was dead.

"I checked to see if she was breathing, I checked to see if she had a heartbeat — and, no, she didn't," he said through tears.

"I thought she was going to kill me. I'd never been in that situation before in my life. I was just in a panic trying to stop her. I was freaked out trying to make sure my son was OK."

Balbar said he didn't call police. Instead, he said he hid Hamill's body in a cooler so his son wouldn't have to see it.

"Then I just sat beside the bed with my son and waited until morning," he said.

Balbar wasn't arrested until more than four years after Hamill's death at the conclusion of a three-month RCMP undercover operation in December 2007.

Court has previously heard Balbar was lured into a fictitious criminal organization — actually comprised entirely of undercover RCMP officers — with promises of money and sex.

The elaborate undercover investigation culminated in Balbar's confession to the supposed leader of the fake gang.

(Kamloops This Week)